In order to provide convenient access to a structure (e.g., a building), doors are frequently installed into the walls thereof. Many doors also have a cooperating door frame with a stop which prevents the door from swinging past the plane of the door frame (i.e., the plane of the wall). For example, if the door is located inboard of the stop, the door will open inwardly (i.e., toward the interior of the structure), but not outwardly (i.e., toward the exterior of the structure). If the door is located outboard of the stop, however, it will open outwardly, but not inwardly. Such outwardly swinging doors are commonly referred to as "exit only doors." Of course, if no stop is provided, the door will open both inwardly and outwardly.
At construction sites, movie theaters, and the like, it is often necessary to positionally constrain (or lock) an exit only door from the inside so that unauthorized entry from the outside is prevented. Although attempts have been made to accomplish this feat, these attempts have proven deficient in many respects. For instance, the door lock devices used at most movie theaters are cumbersome, complicated, and expensive. Such door lock devices also have many parts which makes them difficult to assemble, disassemble, and repair. Moreover, it is often times desirable to provide such door lock devices without padlocks, key operated locking mechanisms, or the like so that the door may be quickly opened from the inside for emergency egress.